Shui‐Tien Chen

Vinyl carboxylate an acylating reagent for selective acylation of amines and diols

Abstract Vinyl group of vinyl alkylate (C=2 or 16) and vinyl benzoate have been found to be a good leaving group in acylation of alcohols (40–50% yield) and amines (in 60–90% yield).

Enzymic synthesis of opioid peptides

Protected opioid pentapeptides were synthesized by the papain-catalyzed condensation of small synthetic fragments. These peptides, free as well as protected, were identical with those prepared by the dicyclohexylcarbodiimide-1-hydroxybenzotriazole method.

Separation of aspartame and its precursor stereoisomers by chiral chromatography

The four stereoisomers of the protected dipeptide, ll-, ld-, dl- and dd-(Z)-Asp(β-Bzl)—Phe-OCH3, an aspartame precursor, were successfully separated by high-performance liquid chromatography with a Chiralcel OC column. Of the four stereoisomers of aspartame, ll-, ld-, dl- and dd-Asp—Phe-OCH3, two pairs of diastereoisomers, dd/dl and ll/ld, cannot be separated by thin-layer chromatography on a CHIRALPLATE, whereas two other pairs of diastereoisomers, dd/ld, and ll/dl, and two pair of enantiomers, dd/ll and dl/ld, could be well separated.